1. Field of the Invention
The present invention relates to a video signal processing apparatus and a video signal processing method, and in particular, relates to a video signal processing apparatus for processing a stereoscopic image signal in order to display a stereoscopic image on a display, and to a video signal processing method.
2. Description of the Background Art
It is known that in a video signal processing apparatus capable of displaying a stereoscopic image on a display using a stereoscopic image signal in which right-eye and left-eye images having a parallax alternate every frame, the interference of an image due to the incapability to completely separate the right-eye and left-eye images from each other, that is, crosstalk, often occurs in the stereoscopic image.
As a conventional technique for solving such a problem, a method of suppressing crosstalk is known (see Japanese Laid-Open Patent Publication No. 8-331600 (Patent Literature 1), for example). The conventional technique removes in advance a value based on the amount of crosstalk from a video signal. Consequently, in the conventional technique, the luminances to reach both eyes of a viewer are made up only of those of an original video signal, which enables the suppression of crosstalk.
As is well known, a video signal processing apparatus capable of displaying a stereoscopic image needs to display right-eye and left-eye images as a pair. Thus, to maintain the smoothness of a moving image comparable to that of the display of a non-stereoscopic image, the stereoscopic image needs to be displayed with twice the speed of the non-stereoscopic image. Consequently, the display time of the stereoscopic image per frame is half that of the non-stereoscopic image, and it is likely that the screen is darker (the luminance is lower) with the stereoscopic image than the non-stereoscopic image. In addition, a viewer is occasionally required to wear 3D glasses because the right-eye and left-eye images are displayed in a separate manner. In this case, however, the transmittance of the 3D glasses reduces the luminance. Thus, when crosstalk is suppressed, it is desirable to reduce the luminance as little as possible.
In the conventional technique disclosed in Patent Literature 1, however, the luminance is made up only of an original video signal by removing crosstalk components, which reduces the luminance of the image in exchange for the suppression of crosstalk.
In addition, in the conventional technique disclosed in Patent Literature 1, if a video signal, which is affected by crosstalk, is a signal of a dark image having a low luminance, it is not possible to remove crosstalk components in advance, which leaves crosstalk.